Field of the Invention
The present invention relates to a composition, a production method of a patterned substrate, a film and a forming method thereof, and a compound.
Discussion of the Background
In manufacturing semiconductor devices, multilayer resist processes have been employed for attaining a high degree of integration. In these processes, a composition for forming a resist underlayer film is first coated on a substrate to provide a resist underlayer film, and then a resist composition is coated on the resist underlayer film to provide a resist film. Thereafter, the resist film is exposed through a mask pattern or the like, and developed with an appropriate developer solution to form a resist pattern. Subsequently, the resist underlayer film is dry-etched using the resist pattern as a mask, and further the substrate is dry-etched using the resultant resist underlayer film pattern as a mask, thereby enabling a desired pattern to be formed on the substrate. Resist underlayer films used in such multilayer resist processes are required to exhibit general characteristics such as optical characteristics, e.g., the refractive index and the extinction coefficient, as well as etching resistance.
In recent years, in order to further increase the degree of integration, microfabrication of patterns has been further in progress. Also in connection with the multilayer resist processes described above, various characteristics as in the following are demanded for resist underlayer films formed, as well as compositions for forming the same. To meet these demands, structures of polymers, etc., contained in the composition, and functional groups included in the polymers have been variously investigated (see Japanese Unexamined Patent Application, Publication No. 2004-177668).
Moreover, the multilayer resist processes involving a procedure of forming a hard mask as an intermediate layer on the resist underlayer film has been contemplated recently. Specifically, since an inorganic hard mask is formed on a resist underlayer film using CVD techniques according to this procedure, particularly in a case where a nitride inorganic hard mask is formed, the temperature is elevated to be as high as at least 300° C. and typically no less than 400° C., and thus, the resist underlayer film is required to have superior heat resistance.
Still further, patterns are more frequently formed recently on a substrate having a plurality of types of trenches, particularly trenches having aspect ratios that differ from each other, the resist underlayer film formed is desired to have these trenches sufficiently embedded thereinto, and also have superior flatness.